An effective colorimetric and fluorescent chemosensor derived from modified curcumin for the detection of the Fe3+ ion

Abstract

From curcumin and 1-aminonaphthalene, the chemosensor NIBMP (4,4'-(3,5-bis(naphthalene-1-ylimino)hepta-1,6-diene-1,7-diyl)bis(2-methoxyphenol)) has been prepared. For Fe³⁺ as opposed to other metal ions, NIBMP serves as both a colorimetric and a fluorescence turn-off sensor. Interactions between NIBMP and Fe³⁺ reveal a noticeable colour shift from yellow to brown. The absorption and fluorescence studies reveal new peaks at 326 nm and quenching at 530 nm, respectively. The limit of detection, 0.139 µM, is found to be significantly lower than the EPA's standard for drinking water (5.37 µM). There is evidence for a 1:1 stoichiometry between NIBMP and Fe³⁺ utilizing Job's plot analysis and ESI-HRMS. Additionally, a Stern-Volmer plot has been created, and its quenching constant has been computed. Moreover, EDTA's fluorescence analysis has been used to test whether the complexation of NIBMP with Fe³⁺ is reversible. Significantly, Fe³⁺ is successfully detected using NIBMP in actual water samples with excellent recoveries.